Any VPN experts?

[jam1et]

Server is SBS 2k fully patched.
Today 2 of the clients PDA's and a Laptop are unable to connect to the server over PPTP VPN (via Vodafone GPRS network). They worked fine last night and nothing on the server or PDA's has changed. 2 remote PC's (win98 and winxp) can still access PPTP VPN successfuly (over an ADSL connection). This makes me think its some kind of problem with Vodafones GPRS network blocking GRE packets?

Have trawled various posts concerning this error and tried all the usual suspects but nothing has resolved it. I can look at the port status and see it trying to authenticate then it just disconnects. So the traffic is getting thru the firewall ok but just not authenticating.

Event ID: 20049
"The user connected to port VPN3-127 has been disconnected because the
authentication process did not complete within the required amount of
time."

I enabled tracing and the RASTAPI.log file contains the entries below. Can anyone deciper them and tell me what might be causing the problem? From what I can tell, one minute its connected, the next minute it isnt. Is there another trace log I should be looking at for more info? The RASAUTH.log doesnt log anything at all when the PDA's try to authenticate but it does log the authentication when the remote PC's connect ok.

Thanks

08] 22:20:12:507: RasTapicallback: linecallstate=0x2
[3908] 22:20:12:507: DwProcessOfferEvent: hcall=0x100dd
[3908] 22:20:12:507: DwProcessOfferEvent: Accepting call on VPN3-127
hcall = 0x100dd
[3908] 22:20:12:507: DwProcessOfferEvent: CurrentDialInClients=0x1
[3908] 22:20:12:507: DwProcessOfferEvent 0x0
[3620] 22:20:12:507: DeviceWork: VPN3-127. State = 2
[3620] 22:20:12:507: DeviceWork: VPN3-127. lineAccept returned 0x100cc
[3908] 22:20:12:507: LINE_REPLY. param1=0x100cc
[3908] 22:20:12:507: RasTapiCallback: Changing Listen State for
VPN3-127 from 2 -> 3
[3620] 22:20:12:507: DeviceWork: VPN3-127. State = 2
[3620] 22:20:12:523: DeviceWork: VPN3-127. lineAnswer returned 0x100bb
[3908] 22:20:12:523: RasTapicallback: linecallstate=0x100
[3908] 22:20:12:523: DwGetConnectInfo
[3908] 22:20:12:523: DwGetIDInformation
[3908] 22:20:12:523: DwGetIDInformation. 0
[3908] 22:20:12:523: SizeRequired for CallID=16
[3908] 22:20:12:523: DwGetIDInformation
[3908] 22:20:12:523: RasTapiCallback: called id info. not avail
[3908] 22:20:12:523: DwGetIDInformation. 0
[3908] 22:20:12:523: DwGetConnectInfo. 0x0
[3908] 22:20:12:523: RasTapiCallback: DwGetConnectInforeturned 0x0
[3908] 22:20:12:523: RasTapiCallback: Connected on VPN3-127
[3908] 22:20:12:523: RasTapiCallback: Incoming Call
[3908] 22:20:12:523: LINE_REPLY. param1=0x100bb
[3620] 22:20:12:523: DeviceWork: VPN3-127. State = 2
[3620] 22:20:12:523: DeviceWork: Changing State for VPN3-127 from 2 ->
3
[4592] 22:20:12:523: PortConnect: VPN3-127
[4592] 22:20:12:523:
[4592] 22:22:12:570: PortDisconnect: VPN3-127
[4592] 22:22:12:570: InitiatePortDisconnection: VPN3-127
[4592] 22:22:12:570: IntiatePortDisconnection: WAN Miniport (PPTP),
CurrenDialedInClients=0x0
[4592] 22:22:12:570: InitiatePortDisconnection: Changing state for
VPN3-127 from 3 -> 5
[4592] 22:22:12:570:
[4592] 22:22:12:570:
[3908] 22:22:13:570: RasTapicallback: linecallstate=0x4000
[3908] 22:22:13:570: RasTapiCallback: LINECALLSTATE - initiating Port
Disconnect
[3908] 22:22:13:570: InitiatePortDisconnection: VPN3-127
[3908] 22:22:13:570: InitiatePortDisconnection: Changing state for
VPN3-127 from 5 -> 5
[3908] 22:22:13:570:
[3908] 22:22:13:570: RasTapicallback: linecallstate=0x1
[3908] 22:22:13:570: LINE_REPLY. param1=0x100aa
[3908] 22:22:13:570: LINE_REPLY. param1=0x10099
[3908] 22:22:13:570: RasTapiCallback: Idle Received for port VPN3-127
[3908] 22:22:13:570: RasTapiCallback: changing state of VPN3-127. 5 ->
1
[3908] 22:22:13:570: RasTapiCallback: lineDeallocateCall for
VPN3-127,hcall = 0x100dd
[3620] 22:22:13:570: PortTestSignalState: DeviceState = 0
[4592] 22:22:13:570: DeviceListen: VPN3-127. State = 1
[4592] 22:22:13:570: DeviceListen: Changing State for VPN3-127 from 1
-> 2
[4592] 22:22:13:570: DeviceListen: Changing Listen State for VPN3-127
from 4 -> 2
[4592] 22:22:13:570:

>>> Edited by jam1et on Thursday 17th June 10:39

[alunr]

Vodafone have just started selling their own vpn product so they might have blocks in place for others...

[jam1et]

Yes I'm sure its something to do with that. I called them last night and they have put a call thru to the engineers but theres a 2 day backlog. The front-line support didnt know what a GRE packet is let alone wheather its been blocked at their firewalls or not.



>> Edited by jam1et on Thursday 17th June 15:19

[marlboro]

The RASTAPI log does not show the trace in enough detail.

It would be worth trying a trace using Ethereal. I've used this for both Ethernet and dial-up connections. However you will need to read the FAQ on tracing from specific interfaces.

www.ethereal.com/

If you do take traces and need any help with the decode please mail me.

[jam1et]

I used Windows Network Monitor to capture packets which is a bit limited. I'll give ethereal a go (provided there is a win32 version) and get back to you with the results. Can I email you the capture file to take a look at?

Cheers

>> Edited by jam1et on Friday 18th June 10:39

[marlboro]

No problem, email from my profile...

[jam1et]

Just in case anyone is interested. I was right in my diagnosis that it was the Vodafone network causing the problem. It turnsd out they were not routing GRE packets. They have fixed it now, only took them a week (after I spent 2 days and and 1 evenings until 11.30pm trying to make sure it wasnt a problem our end). Grrrrrrr!